406 area code
Billings area, Mountain Time.Area code 406 covers Billings, Missoula, Helena and 257 more places in Montana, on Mountain Time.
Right now in Billings
Mountain Time (MST, UTC-7; MDT, UTC-6 in summer)
Calling hours: Every day, 8 AM to 9 PM (the federal rule)
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Where 406 numbers come from
Numbers are issued by rate center, a billing area named for its main town. 406 has 260. Each one's share is how many 406 numbers start there.
- Billings10%
- Missoula6%
- Helena5%
- Great Falls5%
- Bozeman4%
- Kalispell3%
- Butte2%
Also: Miles City, Sidney, Hamilton, Lewistown, Livingston, Dillon, Hardin, Havre, Shelby, Columbus, Glendive, Laurel + 241 more
Share of exchanges (blocks of 10,000 numbers). Source: NANPA rate center and exchange reports, November 10, 2026
When can you call a 406 number?
Sales calls to homes and cell phones have legal hours, set by the federal rule. Hold every 406 number to them, since you can't tell a work line from a personal cell.
What applies to 406Every day, 8 AM to 9 PM
- Federal (TCPA and FTC rule)Every day, 8 AM to 9 PMCalls to residential and mobile numbers. Most calls to businesses are exempt from the FTC's rule.47 CFR 64.1200(c)(1); 16 CFR 310.4(c) (opens in a new tab)
Local time comes from the area code, not from where the person is today. Mobiles keep their number when they move. Calling hours here are a guide, not legal advice. Every state's calling hours, with sources
The 406 area code
406 is one of the original area codes from 1947. Local calls take all 10 digits.
- 1947406 starts
Source: NANPA area code database
Calling a list of 406 numbers?
Paste it into the free phone number validator. It checks every number, finds each one's time zone and sorts the list by who you can call right now.
406 area code FAQ
What area code is 406?
406 is a Montana area code for Billings, Missoula, Helena, Great Falls and 256 more places.
What time zone is the 406 area code in?
Mountain Time (MST, UTC-7; MDT, UTC-6 in summer).
What are the calling hours for 406 numbers?
Every day, 8 AM to 9 PM, local time, under the federal rule.
When did the 406 area code start?
In 1947: it's one of the original area codes.
Calling 406 numbers? Reach more of them.
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